Expandable sheath for transaxillary access

Abstract

The expandable sheaths disclosed herein are adapted to be used in tortuous vessels, such as, but not limited to, the subclavian artery. The sheaths are expandable to facilitate passage of a medical device through a central lumen of the sheath. The sheaths can be used to deliver medical devices, such as implantable heart valves. The methods of delivering a medical device can include transforming a distal region of the expandable sheath to an at least partially bowed configuration and bending a central shaft of the expandable sheath around a bend in vasculature without kinking the sheath.

What is claimed is: 
     
         1 . An expandable sheath comprising:
 a central lumen and a longitudinal axis extending therethrough;   a tubular layer comprising an inferior longitudinal region and a superior longitudinal region; and   a longitudinally extending reinforcement coupled to the inferior longitudinal region and biased to bend in an inferior direction under axial compression, the reinforcement comprising a central axis extending parallel to the longitudinal axis of the sheath;   wherein the sheath is expandable from a collapsed configuration to a radially expanded configuration to facilitate passage of a medical device through the central lumen of the sheath.   
     
     
         2 . The expandable sheath of  claim 1 , wherein the tubular layer further comprises a tapered proximal region, a distal region, and a central shaft extending distally therebetween. 
     
     
         3 . The expandable sheath of  claim 1 , wherein a length of the sheath is from 4 inches to 10 inches. 
     
     
         4 . The expandable sheath of  claim 1 , wherein a durometer of the reinforcement is higher than a durometer of the tubular layer. 
     
     
         5 . The expandable sheath of  claim 1 , wherein the reinforcement is coupled to an external surface of the inferior longitudinal region. 
     
     
         6 . The expandable sheath of  claim 5 , wherein an outer jacket extends over the reinforcement and the tubular layer. 
     
     
         7 . The expandable sheath of  claim 5 , wherein the superior longitudinal region of the tubular layer further comprises at least one longitudinally extending fold. 
     
     
         8 . The expandable sheath of  claim 1 , wherein the reinforcement is arc-shaped at a selected transverse cross section taken perpendicular to the longitudinal axis of the sheath. 
     
     
         9 . The expandable sheath of  claim 8 , wherein at the selected transverse cross section, the reinforcement extends around from 25% of a circumference of the tubular layer to 60% of the circumference of the tubular layer. 
     
     
         10 . The expandable sheath of  claim 1 , wherein the reinforcement comprises a series of longitudinally spaced ribs, each rib comprising left and right intermediate regions extending circumferentially away the central axis of the reinforcement. 
     
     
         11 . The expandable sheath of  claim 10 , wherein each rib of the series of longitudinally spaced ribs is coupled at a left end to a left longitudinally extending spine, and each rib of the series of longitudinally spaced ribs is coupled at a right end to a right longitudinally extending spine. 
     
     
         12 . The expandable sheath of  claim 11 , wherein a selected rib of the series of longitudinally spaced ribs comprises a left extension extending from the left intermediate region and a right extension extending from the right intermediate region, the left extension being coupled to the left longitudinally extending spine and the right extension being coupled to the right longitudinally extending spine. 
     
     
         13 . The expandable sheath of  claim 10 , wherein the intermediate regions of a selected rib widen extending away from the central axis of the reinforcement. 
     
     
         14 . The expandable sheath of  claim 10 , wherein the series of longitudinally spaced ribs define a series of longitudinally spaced gaps, each gap comprising a left side extending circumferentially away from the central axis and a right side extending circumferentially away from the central axis. 
     
     
         15 . The expandable sheath of  claim 14 , wherein the series of longitudinally spaced gaps is bounded on a left end by a left longitudinally extending spine, and the series of longitudinally spaced gaps is bounded on a right end by a right longitudinally extending spine. 
     
     
         16 . The expandable sheath of  claim 14 , wherein the left side of a selected gap comprises a left taper that narrows approaching a left end of the selected gap, and the right side of the selected gap comprises a right taper that narrows approaching a right end of the selected gap. 
     
     
         17 . The expandable sheath of  claim 16 , wherein the left side of a selected gap comprises a widening strain relief portion between the left taper and the left end of the selected gap, and the right side of the selected gap comprises a widening strain relief portion between the right taper and the right end of the selected gap. 
     
     
         18 . The expandable sheath of  claim 1 , wherein the tubular layer further comprises a distal region, the distal region comprising a plurality of longitudinally extending struts, the plurality of longitudinally extending struts at least partially defining a plurality of elongated slits extending through a wall thickness of the distal region. 
     
     
         19 . The expandable sheath of  claim 18 , wherein upon axial compression the distal region transforms to a bowed configuration wherein each elongated slit widens circumferentially and each strut bows radially away from the longitudinal axis, thereby shortening the distal region. 
     
     
         20 . The expandable sheath of  claim 1 , wherein the sheath is bendable from a straight configuration to a bent configuration, both the straight configuration and the bent configuration facilitating unobstructed passage of the medical device through the central lumen of the sheath.